Cutting-knife



(No Model.)

w. E. TAFT.

CUTTING KNIFE.

No. 478381. Patented July 5, 1892.

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UNITED STATES PATENT OFFICE.

WVILLIAM E. TAFT, OF DUNMORE, PENNSYLVANIA.

CUTTlNG-KNIFE.

SPECIFICATION forming part of Letters Patent No. 478381, dated July 5, 1892. Application filed Mas, 8, 1891. Serial No. 392,o56. (No model.)

To all whom it may concrn:

Be it known that I, WILLIAM E. TAFT, a citizen of the United States of America, residing at Dunmore, in the county of Lacka- Wanna and State of Pennsylvania, have invented certain new and useful Improvements in Cutting-Knives, of which the following is a specification.

My said invention relates to the shape of knives used in turning grooved or beaded forms, whether round or polygonal.

The object of my invention is to provide a single knife adapted to cut the bead or groove without binding or rubbing, and also to remove the Wood smoothly by means of a drawing cut caused by the inclination of the edge of the knife to the axis of the revolving head and of the Wood.

My invention is shown in the acoompanying drawings in two different forms or as applied to two different forms of knives.

Figure l shows a plan View of a knife adapted to cut a circumferential groove. Fig.

2 is a transverse section on line a; m of Fig. 1.

Fg. 3 shows a longitudinal section on line y 'y of Fig. 1. Fig. 4: is an edge View of the knife. Fig. 5 is a plan View of a knife adapted to cut a groove circnmferentially. Fig. 6 is a cross-section on line x x of Fig. 5. Fig. 7 is an edge View of the knife. Fg. 8 is a longitudinal section on line y y, and Fig. 9 a longitudinal section on line z z.

These knives, it will be understood, are fitted to be attached to any suitable cuttinghead which has rotary notion and causes the edges of the knives to move in a circular path to cut the Wood arranged across the path of the revolving knives. In the form 'first shown in the drawings the knife is approximately senicircular in cross-section. It is intended to be clamped upon the cutting-head with the curved or convex side upward. Its edge is formed by beveling on the interior, with a full bevel at the max-gin, as shown at a b, Fig. 1. This causes the exterior surface of the knife to be fiush with the cutting-edge of the knife at that point. The beveling dininishes from that point on each side toward the center, where it is least. The outside of the knife is beveled only about the central part of the curve, or between the points c c, as shown in Fig. 4. It is not essential that at the central point of the edge there should be any interior bevel at all, and the bevelon the outside may at that point be full; but itis essential that the bevel at the margins or each end of the edge should be full that is, all the bevel on the inside and the edge fiush with the surface on the outside. The eifect of this is that when the toolisicntting the groove by rotatingagainst a piece of Wood held within the path of its rotation 'the corners or those parts of the edge near the corners or ends of the edge which cut directly across the 'grain of the wood will pass through the groove without binding by reason of the beveling being all on the inside at that point. This is especially useful in turning polygonal forms, where the Wood is moved laterally and'in line with the niotion of the knife and in its operation outs through the groove repeatedly during the lateral movement of the piece which is operated upon.

In Fig. l the lines efindicate the edges of the groove and show the relation of the knife edges to the edge of the groove.

Fig. 5 and the following figures illustrate a form of knife adapted to cut a bead. In this the knife is Secured to the head with the hollow part downward.

I have represented the form of knife adapted to cut an angular bead. In this the sloping parts of the edge g h are fiush with the interior surface' of the knife and-the bevel is wholly on the outside, so that as these parts pass over the bead in their rotary movement they will pass without V binding. The intermediate part of the edge between the inclined part is beveled on the inside, inasmuch as it is at right angles with the plane of revolution and will not bind in any event. In this form of knife it will be observed that the position of the beVels is exactly reversed; but in both 'forms the bevel upon that part of the curved edge next to the ends thereof has the bevel wholly on one side, which is either the outside or inside, according as the knife edge is to cut a groove or a head.

It will be observed in Figs. 1 and 5 that the edge is inclined to the longitudinal axis of the IOO knfe. This is for the purpose of giving a lathes, having an edge of eurved or angnlar drawing cut, Whieh makes snoother or better form with bevels on each side, the bevels at work. the mergim being full and the surface of the I claim as nyinventionknife on the sides opposte said full bevels I 5 5 l. A knfe for the eutting-heads of tnrningbeing plain.

lathes, having an edge of en'ved or angular In testimony Whereof I affix ny signature in form, with the edge beve'l on one side of the presence of two witnesses. blade at the center and on the other side of XVILLIAM E. TAFT. the blade at the nargins, as and for the purwitnesses: IO pose set forth. FREDK. FULLER,

2. A knife for the cuttenheads of iurning- J AS. H. TORREY. 

